Resin solution and method of preparing same



Patented Aug. 11, 1931 UNITED STATES PATENT; OFFICE H. SCHMIDT, OF BLOOMFIELD, NEW JERSEY, ASSIGNOR '10 BAKELITE CORPORA- TION, OF NEW YORK, N. Y., .A. CORPORATION OF DELAWARE RESIN SOLUTION AIli'D METHOD OF PREPARING SAME in Drawing.

This invention relates to varnishes or analogous resin solutions of which the resin base consists wholly or in part of resins of the thiourea-formaldehyde. type. A primary object of the invention is to provide a simple process yieldin directly and by a one-stage operation, a so ution of a thiourea resin which is potentially reactive in character, that is to sa' capable of becoming 1o infusible, and practicall insoluble in comiion solvents, upon app ication of sufiicient eat.

Following is a typical and preferred em- .bodiment of the invention, it being understood however that the invention is not limited to the particular proportions of. 1 materials, solvents, or manipulations as described: v,

100 parts by weight-of thiourea are disz'o solved in a mixture consisting of 100 parts each of ethyl lactate and the mono-ethyl ether of ethylene glycol. 60 parts by weight of paraform' are added and the mixture heated to; its boiling point or somewhat less asunder a reflux condenser for two to three hours; The resulting solution is filtered and is directly utilizable as a varnish or lacquer; The thiourea in-theabove example ma be partly replaced by urea. he roportionfof solvent used will of course ependupon the; particular application or use for which the varnish orresin solution is intended. Such applications inelude the impregnationofvfibrous or other fillers for the manufacture of molding mixttres; the coating or impregnationhof sheets- '5 o comprising effecting a reaction between.

paper or cloth for the manufacture of g laminated products; admixture with appropriate solvents or thinnersfor the prepara- Application flled May 7, 1927. Serial No. 189,748.

thiourea and an anhydrous methylene containing hardening agent in the presence of a solvent comprising at least onesubstanoe of the group consistlng of ethyl lactate and the mono-ethyl ether of ethylene glycol, said hardenin resin of t e reactive type.

2. Process of preparing a resin solution agent proportioned to yield; a

comprising efiecting a reaction between 1 thiourea and paraform in the presence of a solvent comprising at least one substance ,I of the 'grou consist in of ethyl lactate and the mono-et yl ether 0 ethylene glycol said parafor'm proportioned to yield a resm o f the reactive type.

In testimony whereof, I afi'ix my slgnature.

JOHN H. SCHMIDT.

reactive 

